A method for compensating temperature drift noise of an optical current sensor

Abstract

This invention relates to a method for compensating for temperature drift noise in an optical current sensor, comprising the following steps: A laser emits an optical signal, which passes sequentially through a polarizer, a magneto-optical crystal, an S-wave plate, and an analyzer. Under the influence of the current to be measured, the output signal is superimposed with the temperature drift noise and the Faraday magneto-rotation angle, forming a shifted stripe-shaped light spot. The displacement of the stripe-shaped light spot is located using an image sensor to measure the superposition angle of the temperature drift noise and the Faraday magneto-rotation angle. Based on the measured value of the superposition angle, the current value of the AC current to be measured output by the optical current sensor is calculated, and the waveform of the output current is sinusoidally fitted using the least squares method. The average value of the corresponding times of adjacent peaks and troughs in the waveform is calculated to determine the zero-crossing time of the AC current to be measured. At the zero-crossing time, the superposition angle of the Faraday magneto-rotation angle is obtained as the temperature drift noise. The obtained temperature drift noise is used to compensate for the fitted waveform of the output current to obtain a denoised AC current waveform.

Description

Technical Field

[0001] This invention relates to a method for compensating for temperature drift noise in an optical current sensor, belonging to the field of optical current sensor calibration technology. Background Technology

[0002] Optical current sensors, employing optical sensing technology, offer advantages over electromagnetic current transformers, including superior insulation, faster response, absence of transient magnetic saturation, wider operating bandwidth, and digital signal processing, making them promising for future applications. However, temperature variations and vibrations induce stress line birefringence (temperature drift noise) in the magneto-optical crystal and transmission fiber, which is superimposed on the Faraday magnetostrictive rotation angle, introducing measurement errors. Existing optical current sensors utilize a polarized interferometry detection mode based on Malus's law, which has a limited measurement range for the Faraday magnetostrictive rotation angle. This results in a greater weighting of temperature drift noise on the measurement results, potentially even obscuring valuable information. Furthermore, the polarized interferometry detection mode causes the Faraday magnetostrictive rotation angle and temperature drift noise to nonlinearly superimpose, making noise signal separation and compensation difficult and severely compensating for the noise, thus significantly impairing the accuracy and stability of optical current sensor measurements.

[0003] To address the issue of temperature drift noise, existing research has proposed numerous methods, such as using novel special optical fibers as sensing fibers. These fibers, processed with special techniques, can effectively suppress linear birefringence, including polygonal polarization-maintaining photonic crystal fibers, annealed fibers, and twisted fibers. However, the fabrication processes for these novel special fibers are complex and costly, making them difficult to apply universally in optical current sensors. Another approach involves using a backpropagation (BP) neural network to map the complex relationship between the output current of the optical current sensor, the measured current, and linear birefringence, followed by algorithmic compensation. However, due to the lack of universality in the training samples, this model also lacks general applicability. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention proposes a method for compensating for temperature drift noise in optical current sensors.

[0005] The technical solution of the present invention is as follows:

[0006] On one hand, the present invention provides a method for compensating for temperature drift noise in an optical current sensor, the optical current sensor comprising a laser, a polarizer, a magneto-optical crystal, an S-wave plate, and an analyzer arranged sequentially on the same optical path, the method comprising the following steps:

[0007] The laser emits an optical signal, which passes sequentially through a polarizer, a magneto-optical crystal, an S-wave plate, and an analyzer. Under the influence of the current to be measured, the output signal is superimposed with temperature drift noise and Faraday magneto-optical rotation angle, forming a shifted strip-shaped light spot.

[0008] The displacement of the strip-shaped light spot is located using an image sensor to measure the superposition angle of temperature drift noise and Faraday magneto-optical rotation angle.

[0009] The measured AC current value output by the current optical current sensor is calculated based on the superposition angle of temperature drift noise and Faraday magneto-optical rotation angle, and the waveform of the output current is sinusoidally fitted by the least squares method.

[0010] The average value of the corresponding times of adjacent peaks and troughs in the waveform of the fitted output current is calculated to determine the zero-crossing time of the AC current under test. At the zero-crossing time, the superposition angle of temperature drift noise and Faraday magneto-optical rotation angle is measured as the temperature drift noise.

[0011] The waveform of the fitted output current is compensated by the acquired temperature drift noise to obtain the denoised AC current waveform under test.

[0012] In a preferred embodiment, the method for measuring the superposition angle of temperature drift noise and Faraday magnetostrictive angle by locating the displacement of the strip-shaped light spot using an image sensor is specifically as follows:

[0013] The initial position of the center of the striped light spot dark pattern is located using an image sensor;

[0014] When measuring the AC current to be measured, the current position of the center of the dark stripe of the light spot is located by the image sensor, and the light spot displacement Δx is calculated by the current position and the initial position.

[0015] The superposition angle of the Faraday magneto-rotation angle is obtained based on the relationship between the spot displacement Δx, the temperature drift noise, and the superposition angle of the Faraday magneto-rotation angle.

[0016] In a preferred embodiment, the relationship between the spot displacement Δx and the superposition angle of the temperature drift noise and the Faraday magnetostrictive angle is specifically as follows:

[0017]

[0018] Where l represents the length of the S-wave plate window.

[0019] On the other hand, the present invention also provides a compensation system for temperature drift noise of an optical current sensor, wherein the optical current sensor includes a laser, a polarizer, a magneto-optical crystal, an S-wave plate, and an analyzer arranged sequentially on the same optical path, and the system includes:

[0020] The startup module is used to emit light signals from the laser, which pass through the polarizer, magneto-optical crystal, S-wave plate and analyzer in sequence. Under the action of the current to be measured, the output signal is superimposed with temperature drift noise and Faraday magneto-optical rotation angle to form a translated strip-shaped light spot.

[0021] The measurement module is used to measure the superposition angle of temperature drift noise and Faraday magneto-optical rotation angle by locating the displacement of the strip-shaped light spot through an image sensor.

[0022] The fitting module is used to calculate the measured AC current value output by the current optical current sensor based on the measured value of the superposition angle of temperature drift noise and Faraday magneto-optical rotation angle, and to fit the waveform of the output current by least squares sine fitting.

[0023] The temperature drift noise determination module is used to calculate the average value of the corresponding times of adjacent peaks and troughs in the waveform of the fitted output current in order to determine the zero-crossing time of the AC current under test. At the zero-crossing time, the measured value of the superposition angle of temperature drift noise and Faraday magneto-optical rotation angle is obtained as the temperature drift noise.

[0024] The compensation module is used to compensate the waveform of the fitted output current by acquiring the temperature drift noise, so as to obtain the noise-reduced AC current waveform to be measured.

[0025] In a preferred embodiment, the measurement module specifically includes:

[0026] The initial position measurement unit locates the initial position of the center of the striped light spot dark pattern using an image sensor;

[0027] The spot displacement calculation unit locates the current position of the center of the dark stripe of the stripe spot by using an image sensor when measuring the AC current to be measured, and calculates the spot displacement Δx by using the current position and the initial position.

[0028] The superposition angle calculation unit obtains the superposition angle of the Faraday magneto-optical rotation angle based on the relationship between the spot displacement Δx, the temperature drift noise, and the superposition angle of the Faraday magneto-optical rotation angle.

[0029] In a preferred embodiment, the relationship between the spot displacement Δx and the superposition angle of the temperature drift noise and the Faraday magnetostrictive angle is specifically as follows:

[0030]

[0031] Where l represents the length of the S-wave plate window.

[0032] In another aspect, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for compensating for temperature drift noise of an optical current sensor as described in any embodiment of the present invention.

[0033] In another aspect, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for compensating for temperature drift noise of an optical current sensor as described in any embodiment of the present invention.

[0034] The present invention has the following beneficial effects:

[0035] This invention discloses a method for compensating for temperature drift noise in an optical current sensor. The optical current sensor is based on an S-wave plate and can linearly demodulate the Faraday magnetostrictive rotation angle. When temperature drift noise exists, its output is a linear superposition of the Faraday magnetostrictive rotation angle and the temperature drift noise. The least squares method is used to fit a sine curve to the output signal of the optical current sensor, and the average value of the corresponding times of adjacent peaks and troughs is calculated to determine the zero-crossing time of the AC current to be measured, thereby obtaining and eliminating the temperature drift noise at this time. Attached Figure Description

[0036] Figure 1 This is a flowchart of the method according to Embodiment 1 of the present invention;

[0037] Figure 2 This is a schematic diagram illustrating the principle of temperature drift noise compensation in an embodiment of the present invention.

[0038] Figure 3 The simulation result of the output light spot of the optical current sensor is shown in the figure.

[0039] The attached figures are labeled as follows:

[0040] 1. Laser; 2. Polarizer; 3. Magneto-optical crystal; 4. S-wave plate; 5. Analyzer; 6. Image sensor; 7. Fitted output current waveform; 8. Temperature drift noise; 9. Noise-reduced AC current waveform under test. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] It should be understood that the step numbers used in the text are for ease of description only and are not intended to limit the order in which the steps are performed.

[0043] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0044] The terms “comprising” and “including” indicate the presence of the described feature, whole, step, operation, element and / or component, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0045] The term “and / or” refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes these combinations.

[0046] Example 1:

[0047] See Figure 1 and Figure 2 A method for compensating for temperature drift noise in an optical current sensor, the optical current sensor comprising a laser 1, a polarizer 2, a magneto-optical crystal 3, an S-wave plate 4, and an analyzer 5 arranged sequentially on the same optical path, the method comprising the following steps:

[0048] S100: A laser emits a light signal, which is sequentially polarized by polarizer 2 to obtain linearly polarized light. Under the influence of the magnetic field of the AC current to be measured, the polarization plane of the linearly polarized light rotates as it passes through magneto-optical crystal 3. The angle of rotation is the Faraday magnetostrictive rotation angle, which is proportional to the AC current to be measured. The emitted linearly polarized light passes through S-wave plate 4 and analyzer 5 to output a stripe-shaped light spot, converting the rotation of the polarization plane into a linear translation of the alternating bright and dark stripe-shaped light spot. Temperature changes and vibrations generate stress line birefringence, i.e., temperature drift noise 8, in the magneto-optical crystal and transmission optical fiber, which is superimposed on the Faraday magnetostrictive rotation angle, thus introducing measurement error.

[0049] S200. The center position of the dark stripe of the striped light spot is located by the image sensor 6, thereby calculating the displacement of the striped light spot. The superposition angle of the temperature drift noise 8 and the Faraday magneto-optical rotation angle is measured based on the displacement of the striped light spot.

[0050] S300: Calculate the measured AC current value output by the current optical current sensor based on the measured value of the superposition angle of temperature drift noise and Faraday magneto-optical rotation angle, and fit the waveform of the output current by least squares sine fitting.

[0051] S400. Calculate the average value of the corresponding times of adjacent peaks and troughs in the waveform 7 of the fitted output current to determine the zero-crossing time of the AC current to be measured. When the AC current to be measured crosses zero, the Faraday magneto-optical rotation angle is also zero. At this time, the temperature drift noise 8 can be separated. Therefore, the measured value of the superposition angle of the temperature drift noise and the Faraday magneto-optical rotation angle at the zero-crossing time is used as the temperature drift noise.

[0052] S500: The waveform 7 of the fitted output current is compensated by the acquired temperature drift noise 8 to obtain the noise-reduced AC current waveform 9.

[0053] In a preferred embodiment of this example, in step S200, the method for measuring the superposition angle of temperature drift noise and Faraday magnetostrictive angle by locating the displacement of the strip-shaped light spot using an image sensor is specifically as follows:

[0054] S201. Locate the initial position of the center of the striped light spot dark pattern using the image sensor;

[0055] S202. When measuring the AC current to be measured, the current position of the center of the dark stripe of the stripe is located by the image sensor, and the spot displacement Δx is calculated by the current position and the initial position.

[0056] S203. Obtain the superposition angle of Faraday magneto-optical rotation based on the relationship between the spot displacement Δx, the temperature drift noise, and the superposition angle of Faraday magneto-optical rotation.

[0057] In a preferred embodiment of this invention, the relationship between the spot displacement Δx and the superposition angle of the temperature drift noise and the Faraday magnetostrictive angle is specifically as follows:

[0058]

[0059] Where l represents the length of the S-wave plate window.

[0060] Based on the above embodiments, this invention is based on a linear measurement mode and least squares fitting, which can extract and compensate for temperature drift noise when the AC current crosses zero. The optical current sensor is based on an S-waveplate and can linearly demodulate the Faraday magnetostrictive rotation angle. When temperature drift noise exists, its output is a linear superposition of the Faraday magnetostrictive rotation angle and the temperature drift noise. According to the Faraday magneto-optical effect, when the AC current to be measured crosses zero, the Faraday magnetostrictive rotation angle of the magneto-optical material is also zero. At this time, the output signal of the optical current sensor is the temperature drift noise. The output signal of the optical current sensor is fitted with a sine curve using the least squares method, and the average value of the corresponding times of adjacent peaks and troughs is calculated to determine the time when the AC current to be measured crosses zero, thus obtaining and eliminating the temperature drift noise at this time.

[0061] The implementation principle of this embodiment is as follows:

[0062] like Figure 2 As shown, the azimuth angles of polarizer 2, S-wave plate 4, and analyzer 5 are 90°, 0°, and 0° respectively.

[0063] The transmission axis of polarizer 2 is located in the y-direction. The laser light passing through polarizer 2 forms linearly polarized light E1, which can be expressed using the Jones matrix as follows:

[0064]

[0065] Where A represents light intensity.

[0066] When linearly polarized light passes through magneto-optical crystal 3, its polarization plane rotates under the influence of the magnetic field of the alternating current being measured. The angle of rotation is the Faraday magneto-rotation angle. The transfer matrix J1 is represented as:

[0067]

[0068] Assuming the temperature drift noise of the magneto-optical crystal and the transmission fiber is δ, then J1 is rewritten as J2:

[0069]

[0070] Therefore, the Jones vector E2 of linearly polarized light after passing through the magneto-optical crystal is:

[0071]

[0072] The Jones matrix of the S-wave plate is:

[0073]

[0074] Where x represents the center position of the dark fringe in the emitted light spot; l represents the length of the S-wave plate window. The Jones matrix of the analyzer is:

[0075]

[0076] Therefore, after the emitted light vector E2 passes through the S-wave plate and the analyzer, we obtain E out :

[0077]

[0078] The emitted light intensity distribution is as follows:

[0079]

[0080] When the following conditions are met:

[0081]

[0082] This corresponds to the position of the dark fringe in the strip-shaped light spot. The center position of the dark fringe in the strip-shaped light spot is located using a CMOS linear image sensor, and the light spot displacement Δx is obtained. Satisfies a linear relationship:

[0083]

[0084] Assuming that the center of the dark fringe is located at the center of the S-wave plate window when Δx = 0, the intensity distribution of the emitted light after polarization analysis of the S-wave plate is obtained based on Matlab simulation, as shown in the attached figure. Figure 3 As shown, the center of the visible light spot dark pattern changes with... The change is synchronized with the translation. Therefore, by measuring Δx, the change can be achieved. Direct and linear measurements.

[0085] In summary, the measurement and demodulation results of the optical current sensor based on the S-wave plate are as follows: The magnetic field H of the measured alternating current is linearly superimposed with δ. According to the Faraday magneto-optical effect, the magnetic field H of the measured alternating current is related to δ. satisfy:

[0086]

[0087] Where V is the Wilder constant, and L is the path length of the light transmitted through the magneto-optical material along the direction of the magnetic field. Therefore, when H = 0... When the alternating current crosses zero, the output signal of the optical current sensor is δ, which can be detected and compensated at this moment.

[0088] The following relationship exists between H and the current i to be measured:

[0089]

[0090] Where L gap This is the air gap length of the iron core.

[0091] Taking into account the influence of temperature drift noise, combining equations (10) and (11), we get:

[0092]

[0093] Based on the spot positioning results of the CMOS linear image sensor, the value of the AC current to be measured is calculated using formula (12). The output current is then fitted using the least squares sine method to calculate the average value of adjacent peak-trough times, thus determining the zero-crossing time of the AC current to be measured. When the AC current to be measured crosses zero, At this point, the temperature drift noise can be separated, and by compensating for it, the denoised waveform of the measured current can be obtained.

[0094] In this embodiment, the laser is a distributed feedback semiconductor light source with a wavelength of 980nm; the length and width of the S-wave plate working window are 2l=20mm and m=4mm, respectively; the CMOS linear array image sensor is DLIS2K, with an applicable wavelength range of 300-1100nm.

[0095] To verify the effectiveness of the method proposed in this embodiment, a high and low temperature alternating damp heat test chamber was used to provide different temperature environments, ranging from -40℃ to 485℃, with a temperature fluctuation of ±0.5℃. In this example, the main optical components were placed inside the chamber, and temperature cycling experiments were conducted within the range of -40℃ to 485℃. The temperature drift noise for each cycle was determined and compensated using the least squares method. Finally, the basic accuracy of the optical current sensor was recorded using a calibrator, as shown in Table 1. Under temperature cycling conditions, the optical current sensor can meet the 0.5-level accuracy requirement.

[0096] Table 1. Basic Accuracy Experimental Data

[0097]

[0098] Example 2:

[0099] This embodiment provides a system for compensating for temperature drift noise in an optical current sensor. The optical current sensor includes a laser, a polarizer, a magneto-optical crystal, an S-wave plate, and an analyzer, all arranged sequentially on the same optical path. The system includes:

[0100] The startup module is used to emit light signals from the laser, which pass sequentially through a polarizer, a magneto-optical crystal, an S-wave plate, and an analyzer. Under the action of the current to be measured, the output signal is superimposed with temperature drift noise and Faraday magneto-optical rotation angle to form a translated strip-shaped light spot. This module is used to implement the function of step S100 in Embodiment 1, which will not be described in detail here.

[0101] The measurement module is used to measure the superposition angle of temperature drift noise and Faraday magneto-optical rotation angle by locating the displacement of the strip-shaped light spot through the image sensor; this module is used to implement the function of step S200 in Embodiment 1, which will not be described again here;

[0102] The fitting module is used to calculate the measured AC current value output by the current optical current sensor based on the measured value of the superposition angle of temperature drift noise and Faraday magneto-optical rotation angle, and to fit the waveform of the output current using the least squares sine method; this module is used to implement the function of step S300 in Embodiment 1, which will not be described in detail here.

[0103] The temperature drift noise determination module is used to calculate the average value of the corresponding times of adjacent peaks and troughs in the waveform of the fitted output current in order to determine the zero-crossing time of the AC current under test. At the zero-crossing time, the measured value of the superposition angle of temperature drift noise and Faraday magneto-optical rotation angle is obtained as the temperature drift noise. This module is used to implement the function of step S400 in Example 1, which will not be described in detail here.

[0104] The compensation module is used to compensate the waveform of the fitted output current by acquiring the temperature drift noise, so as to obtain the noise-reduced AC current waveform to be measured; this module is used to implement the function of step S500 in Embodiment 1, which will not be described in detail here.

[0105] In a preferred embodiment of this invention, the measurement module specifically includes:

[0106] The initial position measurement unit locates the initial position of the center of the striped light spot dark pattern using an image sensor;

[0107] The spot displacement calculation unit locates the current position of the center of the dark stripe of the stripe spot by using an image sensor when measuring the AC current to be measured, and calculates the spot displacement Δx by using the current position and the initial position.

[0108] The superposition angle calculation unit obtains the superposition angle of the Faraday magneto-optical rotation angle based on the relationship between the spot displacement Δx, the temperature drift noise, and the superposition angle of the Faraday magneto-optical rotation angle.

[0109] In a preferred embodiment of this invention, the relationship between the spot displacement Δx and the superposition angle of the temperature drift noise and the Faraday magnetostrictive angle is specifically as follows:

[0110]

[0111] Where l represents the length of the S-wave plate window.

[0112] Example 3:

[0113] This embodiment proposes an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements a method for compensating for temperature drift noise of an optical current sensor as described in any embodiment of the present invention.

[0114] Example 4:

[0115] This embodiment proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements a method for compensating for temperature drift noise in an optical current sensor as described in any embodiment of the present invention.

[0116] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, A and B simultaneously, or B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0117] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0118] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0119] In the several embodiments provided in this application, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0120] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method of compensating for temperature drift noise of an optical current sensor, characterized by, The optical current sensor comprises a laser, a polarizer, a magneto-optic crystal, an S wave plate and a polarimeter arranged in sequence in the same optical path, and the method comprises the following steps: The laser emits an optical signal, which sequentially passes through the polarizer, the magneto-optic crystal, the S wave plate and the polarimeter, and under the action of the measured current, the output signal is superimposed with the temperature drift noise and the Faraday magneto-optical rotation angle, forming a translated bar-shaped light spot; The displacement of the bar-shaped light spot is located by the image sensor to measure the superposition angle of the temperature drift noise and the Faraday magneto-optical rotation angle; The measured alternating current value output by the current optical current sensor is calculated according to the measurement value of the superposition angle of the temperature drift noise and the Faraday magneto-optical rotation angle, and the waveform of the output current is fitted by the least square method; The average value of the adjacent wave peak-valley corresponding time points in the fitted output current waveform is calculated to determine the zero-crossing point of the measured alternating current, and the measurement value of the superposition angle of the temperature drift noise and the Faraday magneto-optical rotation angle at the zero-crossing point is obtained as the temperature drift noise; The fitted output current waveform is compensated by the obtained temperature drift noise to obtain the denoised measured alternating current waveform.

2. The method of claim 1, wherein the method further comprises: The method for measuring the superposition angle of the temperature drift noise and the Faraday magneto-optical rotation angle by locating the displacement of the bar-shaped light spot by the image sensor is specifically: The initial position of the dark stripe center of the bar-shaped light spot is located by the image sensor; In the measurement of the measured alternating current, the current position of the dark stripe center of the bar-shaped light spot is located by the image sensor, and the light spot displacement Δx is calculated by the current position and the initial position; The superposition angle of the Faraday magneto-optical rotation angle is obtained based on the relationship between the light spot displacement Δx and the superposition angle of the temperature drift noise and the Faraday magneto-optical rotation angle.

3. The method of claim 2, wherein the method further comprises: The relationship between the light spot displacement Δx and the superposition angle of the temperature drift noise and the Faraday magneto-optical rotation angle is specifically: Wherein, l represents the length of the S wave plate window.

4. A system for compensating for temperature drift noise in an optical current sensor, characterized by The optical current sensor comprises a laser, a polarizer, a magneto-optic crystal, an S wave plate and a polarimeter arranged in sequence in the same optical path, and the system comprises: The starting module is used to emit an optical signal by the laser, which sequentially passes through the polarizer, the magneto-optic crystal, the S wave plate and the polarimeter, and under the action of the measured current, the output signal is superimposed with the temperature drift noise and the Faraday magneto-optical rotation angle, forming a translated bar-shaped light spot; The measurement module is used to measure the superposition angle of the temperature drift noise and the Faraday magneto-optical rotation angle by locating the displacement of the bar-shaped light spot by the image sensor; The fitting module is used to calculate the measured alternating current value output by the current optical current sensor according to the measurement value of the superposition angle of the temperature drift noise and the Faraday magneto-optical rotation angle, and to fit the waveform of the output current by the least square method; The temperature drift noise determination module is used to calculate the average value of the adjacent wave peak-valley corresponding time points in the fitted output current waveform to determine the zero-crossing point of the measured alternating current, and to obtain the measurement value of the superposition angle of the temperature drift noise and the Faraday magneto-optical rotation angle at the zero-crossing point as the temperature drift noise; The compensation module is used to compensate the fitted output current waveform by the obtained temperature drift noise to obtain the denoised measured alternating current waveform.

5. The system for compensating temperature drift noise of an optical current sensor according to claim 4, wherein, The measurement module specifically comprises: An initial position measurement unit measures an initial position of a center of a dark fringe of a bar-shaped light spot by an image sensor; A light spot displacement calculation unit measures a current position of the center of the dark fringe of the bar-shaped light spot by the image sensor when measuring an alternating current to be measured, and calculates a light spot displacement amount Δx based on the current position and the initial position; An overlay angle calculation unit acquires an overlay angle of the Faraday magneto-optical rotation angle based on a relationship between the light spot displacement amount Δx and the overlay angle of the Faraday magneto-optical rotation angle and the temperature drift noise.

6. The system for compensating temperature drift noise of an optical current sensor according to claim 5, wherein, The relationship between the light spot displacement amount Δx and the overlay angle of the Faraday magneto-optical rotation angle and the temperature drift noise is specifically: Wherein, l represents a length of a window of an S wave plate.

7. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to implement the compensation method for the temperature drift noise of the optical current sensor according to any one of claims 1 to 3.

8. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the compensation method for the temperature drift noise of the optical current sensor according to any one of claims 1 to 3.

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